Method and apparatus for alerting a user to sensed lateral forces upon a guide-sleeve in a robot surgical system

Abstract

Methods and apparatus for detecting or predicting surgical tool-bone skiving are disclosed. In some embodiments, the surgical tool is movably and/or snugly disposed within a guide-sleeve. In some embodiments, a magnitude of a lateral force between the surgical tool and the guide-sleeve is measured (e.g. by a force sensor or strain sensor). The present or future skiving may be detected or predicted according to the magnitude of the lateral force. In some embodiments, an alert signal is generated in response to the detecting or predicting of the skiving.

What is claimed is: 
     
       1. A system for performing a surgical procedure at a surgical site, the system comprising:
 a. a guide-sleeve defining axial and lateral directions; 
 b. a surgical tool movably and/or snugly disposed within the guide-sleeve so that an alignment direction of the surgical tool is determined by that of the guide-sleeve; 
 c. a skiving-detector configured to detect current and potential tool-bone skiving by the surgical tool, according to a magnitude of a lateral force between the surgical tool and the guide-sleeve or according to an indication of the lateral force magnitude; 
 d. a position/orientation controller configured to use a comparison of any said detection to a threshold to predict skiving, wherein said threshold is selected to indicate an elevated risk of skiving; and 
 e. an alerter configured to generate an alert signal upon a positive current detecting of skiving, or a positive predicting of skiving. 
 
     
     
       2. A method of preventing misalignment of a surgical instrument during its operation, said surgical instrument used to perform a surgical procedure at a surgical site, the method comprising:
 a. orienting and/or positioning a guide sleeve in a target orientation, said surgical instrument movably and/or snugly disposed within said guide-sleeve so that an alignment direction of said surgical tool is determined by that of said guide-sleeve; 
 b. at a time when the surgical instrument is disposed within the guide sleeve, measuring, using a skiving-detector configured to detect current and potential tool-bone skiving by said surgical instrument, a magnitude of a lateral force between said surgical instrument and said guide sleeve or an indication of the lateral force magnitude; 
 c. contingent upon the results of the measuring indicating that the lateral force magnitude or said indication thereof exceeds a threshold selected to indicate an elevated risk of skiving, generating an alert signal to indicate a positive current detecting of skiving, or a positive predicting of skiving; and 
 d. if said alert signal is generated, refraining from operation of said surgical instrument. 
 
     
     
       3. The method of  claim 2  wherein the orienting and/or positioning of the guide sleeve is performed robotically. 
     
     
       4. The method of  claim 2  wherein the magnitude of the lateral force is indicative of at least one of a (i) a degree of bone flexibility; and (ii) a degree of flexibility by of the mounted object upon which the surgical robot is mounted on the bone. 
     
     
       5. The method of  claim 2  wherein the surgical instrument is a surgical cannula. 
     
     
       6. The method of  claim 2  wherein the surgical instrument comprises at least one of: (i) a plurality of teeth at a distal end thereof and (ii) a knurled knob at a proximal end thereof. 
     
     
       7. The method of  claim 2  wherein the surgical tool instrument is selected from the group consisting of a drill, a reamer, a biopsy needle, forceps and an endoscope. 
     
     
       8. The method of  claim 2  wherein the lateral force is at least partially caused by, or is primarily caused by, soft tissue pressure upon an inner sleeve within the guide sleeve. 
     
     
       9. The method of  claim 8  wherein the inner sleeve is a surgical cannula. 
     
     
       10. The method of  claim 2  wherein the measurement of the lateral force is performed by a force-meter deployed in an annular region outside of the inner sleeve and within the outer sleeve. 
     
     
       11. The method of  claim 2  wherein the measurement of the indication of the lateral force is performed by a strain-meter configured to sense a strain upon the guide-sleeve. 
     
     
       12. The system of  claim 1  wherein the skiving-detector comprises a strain-meter configured to sense a strain upon the guide-sleeve. 
     
     
       13. The system of  claim 12 , wherein said strain-meter is disposed on the outer surface of said guide-sleeve, and wherein said indication of said lateral force is a measurement of strain upon said outer surface of said guide-sleeve. 
     
     
       14. The method of  claim 11 , wherein said strain-meter is disposed on the outer surface of said guide-sleeve and wherein said indication of said lateral force is a measurement of strain upon said outer surface of said guide-sleeve. 
     
     
       15. The method of  claim 2 , wherein said elevated risk of skiving is an elevated risk that the orientation of said surgical instrument does not match said target orientation.